000 AXPZ20 KNHC 191003 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE JUL 19 2011 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURES... TROPICAL STORM DORA IS CENTERED NEAR 11.4N 95.9W AT 19/0900 UTC OR ABOUT 300 MI S OF PUERTO ANGEL MEXICO...MOVING W AT 14 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 996 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. CONVECTION HAS INCREASED OVERNIGHT...WITH NUMEROUS MODERATE TO STRONG WITHIN 210 NM NE SEMICIRCLE WHILE SCATTERED MODERATE ISOLATED STRONG WAS WITHIN 210 NM SW SEMICIRCLE. ADDITIONAL RAINBANDS OF SCATTERED MODERATE TO STRONG CONVECTION EXTENDED FROM 120 TO 450 NM ACROSS THE NW QUADRANT AND WERE MOVING W ACROSS SOUTHERN MEXICO. DORA REMAINS IN AN ENVIRONMENT CONDUCIVE FOR INTENSIFICATION AND IS EXPECTED TO BECOME A HURRICANE THIS AFTERNOON AND INTENSIFY FURTHER OVER THE NEXT 2 TO 3 DAYS AS IT MOVES WNW. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP4/ WTPZ24 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ALONG 10N ACROSS THE FAR SW CARIBBEAN W ACROSS COSTA RICA TO THE E PERIPHERY OF TROPICAL STORM DORA NEAR 11N91W...THEN RESUMES NW OF DORA NEAR 14N97W TO 17N107W TO BROAD LOW TO MID LEVEL LOW PRES WITH SURFACE CENTER NEAR 18N111W. MONSOON TROUGH RESUMES S OF THIS LOW NEAR 15N11W TO 10N117W TO NEAR 08N140W THEN TRANSITIONS TO THE ITCZ W OF 140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS NOTED FROM 07N TO 11.5N BETWEEN 104W AND 122W...AND FROM 08N TO 10N BETWEEN 129W AND 135W. ...DISCUSSION... A WEAKENING COLD FRONT HAS DISSIPATED ACROSS THE FAR NW PORTIONS OF THE AREA...WITH THE PRIMARY IMPACT OF WINDS SHIFTING TO NE AT AROUND 15 KT AND SEAS BUILDING TO 6 TO 7 FT. THIS FRONT IS DISRUPTING THE USUAL PRESSURE GRADIENT BETWEEN THE SUBTROPICAL HIGH AND RIDGE GENERALLY N OF 15N AND THE ITCZ/MONSOON TROUGH ALONG 10N. AS A RESULT NE TRADE WINDS REMAIN LESS THAN 20 KT N OF THE ITCZ AND MONSOON TROUGH W OF 115W. A 1008 MB SURFACE LOW IS CENTERED NEAR 18N111W AND REMAINS EMBEDDED WITHIN A BROAD LOW TO MIDDLE LEVEL CYCLONIC CIRCULATION THAT HAS ANCHORED TO NW END OF THE MONSOON TROUGH FOR SEVERAL DAYS NOW. THE LOW IS EXPECTED TO CONTINUE WEAKENING AS IT DRIFTS NW OVER THE NEXT 24-36 HOURS MOVING OVER MUCH COOLER WATER TEMPERATURES. THE MONSOON TROUGH WILL THEN BREAK DOWN S OF THIS WEAKENING LOW AND REALIGN FARTHER S ALONG 13-14N WED AS DORA APPROACHES. THE MONSOON TROUGH HAS GRADUALLY BECOMING LESS ACTIVE ACROSS THE BASIN DURING THE PAST 48 HOURS AS LOW LEVEL VORTICITY HAS FOCUSED INTO THE FORMATION OF TROPICAL STORM DORA. EXPECT THE MONSOON TROUGH TO SHIFT NORTHWARD E OF DORA AS DORA TRACKS W-NW. THE TROUGH WILL THEN RE-ESTABLISH ITSELF AGAIN NEAR 10N E OF 100W BY WEDNESDAY INTO THURSDAY AS DORA MOVES AWAY. SW MONSOON WINDS WILL CONTINUE TO DIMINISH DURING THE NEXT 48 HOURS BETWEEN 105W AND 120W AS THE MONSOON TROUGH BREAKS UP INTO SHORTER SEGMENTS. ALSO WITH THE BREAK UP OF THIS UNUSUALLY STRONG MONSOON TROUGH OF THE PAST WEEK...AND THE WWD MOTION OF DORA...DEEP LEVEL EASTERLIES WILL RETURN TO CENTRAL AMERICA DURING THE NEXT FEW DAYS AND BRING ABOUT A MORE TYPICAL MID SUMMER WEATHER PATTERN...AND A RETURN TO MORE TYPICAL DIURNAL-NOCTURNAL CYCLES. OTHERWISE...LONG PERIOD SOUTHERLY SWELL IS EXPECTED TO DOMINATE THE MAJORITY OF THE BASIN THROUGH EARLY WEDNESDAY WITH FADING LONG PERIOD SWELLS. THE RETURN OF EASTERLY WINDS TO CENTRAL AMERICA WILL LIKELY BRING FRESH E-NE WINDS THROUGH THE GULF OF PAPAGAYO AND BUILD DOWNSTREAM SEAS TO NEAR 7 FT BY THU MORNING. $$ STRIPLING 000 AXPZ20 KNHC 191003 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE JUL 19 2011 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURES... TROPICAL STORM DORA IS CENTERED NEAR 11.4N 95.9W AT 19/0900 UTC OR ABOUT 300 MI S OF PUERTO ANGEL MEXICO...MOVING W AT 14 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 996 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. CONVECTION HAS INCREASED OVERNIGHT...WITH NUMEROUS MODERATE TO STRONG WITHIN 210 NM NE SEMICIRCLE WHILE SCATTERED MODERATE ISOLATED STRONG WAS WITHIN 210 NM SW SEMICIRCLE. ADDITIONAL RAINBANDS OF SCATTERED MODERATE TO STRONG CONVECTION EXTENDED FROM 120 TO 450 NM ACROSS THE NW QUADRANT AND WERE MOVING W ACROSS SOUTHERN MEXICO. DORA REMAINS IN AN ENVIRONMENT CONDUCIVE FOR INTENSIFICATION AND IS EXPECTED TO BECOME A HURRICANE THIS AFTERNOON AND INTENSIFY FURTHER OVER THE NEXT 2 TO 3 DAYS AS IT MOVES WNW. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCPEP4/ WTPZ24 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ALONG 10N ACROSS THE FAR SW CARIBBEAN W ACROSS COSTA RICA TO THE E PERIPHERY OF TROPICAL STORM DORA NEAR 11N91W...THEN RESUMES NW OF DORA NEAR 14N97W TO 17N107W TO BROAD LOW TO MID LEVEL LOW PRES WITH SURFACE CENTER NEAR 18N111W. MONSOON TROUGH RESUMES S OF THIS LOW NEAR 15N11W TO 10N117W TO NEAR 08N140W THEN TRANSITIONS TO THE ITCZ W OF 140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS NOTED FROM 07N TO 11.5N BETWEEN 104W AND 122W...AND FROM 08N TO 10N BETWEEN 129W AND 135W. ...DISCUSSION... A WEAKENING COLD FRONT HAS DISSIPATED ACROSS THE FAR NW PORTIONS OF THE AREA...WITH THE PRIMARY IMPACT OF WINDS SHIFTING TO NE AT AROUND 15 KT AND SEAS BUILDING TO 6 TO 7 FT. THIS FRONT IS DISRUPTING THE USUAL PRESSURE GRADIENT BETWEEN THE SUBTROPICAL HIGH AND RIDGE GENERALLY N OF 15N AND THE ITCZ/MONSOON TROUGH ALONG 10N. AS A RESULT NE TRADE WINDS REMAIN LESS THAN 20 KT N OF THE ITCZ AND MONSOON TROUGH W OF 115W. A 1008 MB SURFACE LOW IS CENTERED NEAR 18N111W AND REMAINS EMBEDDED WITHIN A BROAD LOW TO MIDDLE LEVEL CYCLONIC CIRCULATION THAT HAS ANCHORED TO NW END OF THE MONSOON TROUGH FOR SEVERAL DAYS NOW. THE LOW IS EXPECTED TO CONTINUE WEAKENING AS IT DRIFTS NW OVER THE NEXT 24-36 HOURS MOVING OVER MUCH COOLER WATER TEMPERATURES. THE MONSOON TROUGH WILL THEN BREAK DOWN S OF THIS WEAKENING LOW AND REALIGN FARTHER S ALONG 13-14N WED AS DORA APPROACHES. THE MONSOON TROUGH HAS GRADUALLY BECOMING LESS ACTIVE ACROSS THE BASIN DURING THE PAST 48 HOURS AS LOW LEVEL VORTICITY HAS FOCUSED INTO THE FORMATION OF TROPICAL STORM DORA. EXPECT THE MONSOON TROUGH TO SHIFT NORTHWARD E OF DORA AS DORA TRACKS W-NW. THE TROUGH WILL THEN RE-ESTABLISH ITSELF AGAIN NEAR 10N E OF 100W BY WEDNESDAY INTO THURSDAY AS DORA MOVES AWAY. SW MONSOON WINDS WILL CONTINUE TO DIMINISH DURING THE NEXT 48 HOURS BETWEEN 105W AND 120W AS THE MONSOON TROUGH BREAKS UP INTO SHORTER SEGMENTS. ALSO WITH THE BREAK UP OF THIS UNUSUALLY STRONG MONSOON TROUGH OF THE PAST WEEK...AND THE WWD MOTION OF DORA...DEEP LEVEL EASTERLIES WILL RETURN TO CENTRAL AMERICA DURING THE NEXT FEW DAYS AND BRING ABOUT A MORE TYPICAL MID SUMMER WEATHER PATTERN...AND A RETURN TO MORE TYPICAL DIURNAL-NOCTURNAL CYCLES. OTHERWISE...LONG PERIOD SOUTHERLY SWELL IS EXPECTED TO DOMINATE THE MAJORITY OF THE BASIN THROUGH EARLY WEDNESDAY WITH FADING LONG PERIOD SWELLS. THE RETURN OF EASTERLY WINDS TO CENTRAL AMERICA WILL LIKELY BRING FRESH E-NE WINDS THROUGH THE GULF OF PAPAGAYO AND BUILD DOWNSTREAM SEAS TO NEAR 7 FT BY THU MORNING. $$ STRIPLING